Panoramic imaging system

ABSTRACT

A panoramic lens includes an aspherical convex surface and an aspherical concave surface. The convex surface includes a transparent portion and an internally reflective portion, and the concave surface also includes a transparent portion and an internally reflective portion. Light from a 360-degree surrounding scene enters the panoramic lens through the transparent portion of the convex surface, is reflected by the internally reflective portion of the concave surface, is reflected by the internally reflective portion of the convex surface, and exits the panoramic lens through the transparent portion of the concave surface as a narrow column of light beams. Light beams containing image data can be provided to the transparent portion of the concave surface, and those beams will follow this same optical path through the panoramic lens in reverse to project a panoramic image out from the transparent region of the convex surface.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to imaging systems, and in particular to apanoramic imaging system for capturing or creating a 360-degreesurrounding panoramic scene.

2. Related Art

Panoramic imaging arrangements have become popular in recent years forpurposes of viewing 360-degree surrounding panoramic scenes. Oldergenerations of panoramic imaging arrangements generally consisted ofrevolving periscope-like constructions having relatively complexmechanisms for revolving them. More recently, stationary panoramicimaging arrangements have been developed.

A stationary panoramic imaging arrangement generally has one or morelenses, each having a vertical axis of revolution, which are used torefract or reflect light received from a 360-degree surroundingpanoramic scene. The lenses alter the direction of the light, afterwhich the light passes through a series of lenses-which are locatedvertically one above the other and which further manipulate the lightby, for example, focusing the light.

The task of receiving light in a sideways direction and altering thedirection of the light so that the light then proceeds in a verticaldirection is a difficult one. Altering the direction of light to such adegree, especially when coming from a 360-degree surrounding scene,oftentimes leads to aberrations in the resulting light. Relativelycomplex lenses and lens arrangements have been developed to provideacceptable images from 360-degree surrounding scenes, but thatcomplexity increases manufacturing and system costs.

Accordingly, it is desirable to provide a highly manufacturable lenssystem for capturing/projecting a 360-degree panoramic surroundingscene.

SUMMARY OF THE INVENTION

A “panoramic lens” is a lens that is capable of changing thesubstantially horizontal light from a 360-degree surrounding field intoa substantially vertical single beam, and vice versa. A panoramic lenstherefore enables the capture and projection of a 360-degree panoramicimage.

According to an embodiment of the invention, a panoramic lens includes aconvex surface about an axis of revolution (i.e., a surface having aconvex profile in a plane of the axis of revolution) and a concavesurface about the axis of revolution (i.e., a surface having a concaveprofile in a plane of the axis of revolution). The simple “two surface”construction of the lens beneficially allows the lens to be molded fromplastic to simplify manufacturing and reduce cost.

The convex surface follows a first aspheric curve, while the concavesurface follows a second aspheric curve. The convex surface ispositioned above the concave surface and includes a transmissive portionsurrounding an internally reflective portion. Similarly, the concavesurface includes an internally reflective portion surrounding atransmissive portion.

When capturing or projecting a 360-degree panoramic image, light entersand exits the lens via the transmissive portions of the first concavesurface and the second concave surface, and undergoes various internalreflections at the internally reflective portions of the convex andconcave surfaces. For example, when capturing a 360-degree surroundingimage, light enters the lens through the transmissive portion of theconvex surface, is refracted towards the internally reflective portionof the concave surface, is reflected towards the internally reflectiveportion of the convex surface, is reflected towards the transmissiveportion of the concave surface, and is refracted by the transmissiveportion of the concave surface as it exits the lens. When projecting a360-degree image, the light path is reversed.

By properly selecting the curvatures of the convex surface and theconcave surface, any desired optical performance can be obtained fromthe panoramic lens. According to an embodiment of the invention, thetransparent portion of the convex surface is preferably capable ofreceiving light for an unbroken included angle of at least 60 degrees ina vertical plane, with the included angle preferably extending from anangle below the horizon to an angle above the horizon.

According to an embodiment of the invention, a reflective coating isapplied to the portions of the convex and concave surfaces to create thereflective surfaces, while the transmissive surfaces of the convex andconcave surfaces are left “clear” (or coated with an anti-reflectivecoating to improve transmission). According to another embodiment of theinvention, only those portions of the convex and concave surfaces thatin the desired optical path are coated with the reflective oranti-reflective coatings. Portions of the lens that are not in thedesired optical path are coated with an absorbing coating to minimizestray light within the lens, thereby enhancing imaging quality.

According to another embodiment of the invention, a panoramic lensincludes two concave surfaces about an axis of revolution and a convexsurface about the axis of revolution, the convex surface beingpositioned between the two concave surfaces. The upper concave surfaceincludes an internally reflective portion, the convex surface includes atransmissive portion, and the lower concave surface includes both aninternally reflective portion and a transmissive portion.

When capturing a 360-degree surrounding image, light enters the lensthrough the transmissive portion of the convex surface, is refractedtowards the internally reflective portion of the lower concave surface,is reflected towards the internally reflective portion of the upperconcave surface, is reflected towards the transmissive portion of thelower concave surface, and is refracted by the transmissive portion ofthe concave surface as it exits the lens. When projecting a 360-degreeimage, the light path is reversed.

According to another embodiment of the invention, a secondary imagingsystem can be positioned to receive the light exiting the transparentportion of the concave surface of the panoramic lens. The secondaryimaging system can comprise a system of lenses or other optical elements(e.g., mirrors or filters) for focusing, correcting astigmatism, colorcorrecting, creating a flat image plane, or otherwise managing theexiting light. The light can be focused onto a photosensing element,such as a chemical-based film or a digital image sensor.

According to another embodiment of the invention, the secondary imagingsystem can provide a source image to the transmissive portion of theconcave surface of the panoramic lens for projection by the panoramiclens as a 360-degree surrounding image.

The present invention will be more fully understood in view of thefollowing description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A a cross-section of a panoramic lens having a partiallyreflective, partially transmissive convex surface and a partiallyreflective, partially transmissive concave surface, according to anembodiment of the invention.

FIG. 1B is a cross-section of a panoramic lens having a reflectiveconcave surface, a transmissive convex surface, and a partiallyreflective, partially transmissive concave surface, according to anotherembodiment of the invention.

FIG. 2 is a cross-section of a panoramic lens having partiallyreflective, partially transmissive, and partially absorbing convex andconcave surfaces, according to another embodiment of the invention.

FIG. 3 is an imaging system including a panoramic lens according to anembodiment of the invention.

FIG. 4 is an example annular image that can be generated from apanoramic scene by the imaging system of FIG. 3, according to anembodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 shows a cross-section of a panoramic lens 100A according to anembodiment of the invention. Panoramic lens 100A is symmetric about anaxis of rotation 101A and includes a convex surface 110A and a concavesurface 120A. Convex surface 110A is “convex” since it exhibits a convexprofile in a plane of axis of rotation 101A (i.e., a plane parallel toaxis of rotation 101A). Similarly, concave surface 120A is “concave”since it exhibits a concave profile in a plane of axis of rotation 101A.

Convex surface 110A is an aspheric surface (i.e., the cross section ofconvex surface 110A follows a first aspheric curve) and includes atransmissive portion 110A(1) (indicated by the thin line) surrounding aninternally reflective portion 110A(2) (indicated by the dark line).Concave surface 120A follows a second aspheric curve and includes aninternally reflective portion 120A(2) (indicated by the dark line)surrounding a transmissive (or refractive) portion 120A(1) (indicated bythe thin line).

Note that specific geometries of the first and second aspheric curveswill depend on the overall design and desired performance of lens 100A.For example, an aspheric surface can be defined by the followingequation:

$\begin{matrix}{z = {\frac{\frac{h^{2}}{r}}{1 + \sqrt{1 - {\frac{h^{2}}{r^{2}}( {{cc} + 1} )}}} + {Dh}^{4} + {Eh}^{6} + {Fh}^{8} + {Gh}^{10}}} & \lbrack 1\rbrack\end{matrix}$where:

$\begin{matrix}{h = \sqrt{x^{2} + y^{2}}} & \lbrack 2\rbrack\end{matrix}$and where x, y, and z are the Cartesian coordinates of the surface (xand y in the plane perpendicular to the axis of rotation and z parallelto the axis of rotation), and constants r (radius of curvature), cc(conical constant), D, E, F, and G (polynomial constants) are selectedbased on the desired characteristics of the aspheric surface. Note that,as indicated by Equation 1, an aspheric surface can even comprise aspherical surface (i.e., setting constants cc, D, E, F, and G equal tozero results in an equation for a sphere of radius r).

Table 1 provides sample constant values for a panoramic lens (e.g., lens100A) having an axial thickness (i.e., thickness along axis of rotation101A) of 18.171 mm, according to an embodiment of the invention. Byincorporating the constant values in Table 1 into Equation 1, thedimensions of surfaces 110A and 120A can be determined.

TABLE 1 SAMPLE CONSTANT VALUES FOR EQUATION 1 Constant Surface 110ASurface 120A r 11.531 mm 15.802 mm cc −0.811179 −4.817717 D −8.3517 ×10⁻⁷ mm⁻³ 6.7256 × 10⁻⁷ mm⁻³ E 3.0011 × 10⁻¹⁰ mm⁻⁵ 3.3104 × 10⁻¹⁰ mm⁻⁵ F2.1066 × 10⁻¹³ mm⁻⁷ 2.0978 × 10⁻¹³ mm⁻⁷ G 5.9933 × 10⁻²¹ mm⁻⁹ 1.1191 ×10⁻²¹ mm⁻⁹

Lens 100A is formed using an optically transparent material, and sointernally reflective portions 110A(2) and 120A(2) can be created bycovering the appropriate portions of lens 100A with a reflective coatingthat reflects light within lens 100A. The reflective coating can be anycoating capable of creating an internally-reflective surface, such asstandard High Reflective (H.R.) coatings (e.g., aluminum, silver, gold)that can be formed using vacuum, chemical, or even sputter deposition,among others. Meanwhile, transmissive portions 110A(1) and 120A(1) cansimply be left uncoated, or can be coated with an anti-reflective (A.R.)coating to improve transmission characteristics.

In use, light from a 360-degree surrounding panoramic scene enters lens100A through transparent portion 110A(1) of convex surface 110A. Theentering light spans an unbroken included angle A1A that can includelight rays from above the horizon (i.e., the plane perpendicular to axisof rotation 101A), such as light ray R11A, and light rays from below thehorizon, such as light ray R12A.

When light enters transparent portion 110A(1), the light is refractedslightly downward at the convex surface towards internally reflectiveportion 120A(2) of concave surface 120A. The light is then reflectedupwards by internally reflective portion 120A(2) towards internallyreflective portion 110A(2) of convex surface 110A, which in turnreflects the light back downwards towards transmissive portion 120A(1)of concave surface 120A, where it exits lens 100A. Refraction at thecurved surface of transmissive portion 120A(1) decreases the angle theexiting light rays make with axis of rotation 101A.

In this manner, a 360-degree surrounding scene can be captured into anarrow column of light beams by (monolithic) lens 100A without anyadditional optical elements. The exiting beams can then be manipulatedand/or captured by secondary optics and an imaging system (both of whichare described in greater detail below). Note that panoramic lens 100Acan also project a 360-degree panoramic image from an image contained ina column of light beams. Directing the column of light beams attransparent portion 120A(1) of concave surface 120A(2) will cause thelight to follow the same path within lens 100A described above withrespect to the image capturing operation described, except in theopposite direction. Therefore, the light beams that enters lens 100A attransparent portion 120A(1) will be projected from transparent portion110A(2) of convex surface 110A as a 360-degree panoramic image.

By incorporating both reflective and transmissive portions into bothconvex surface 110A and concave region 120A, panoramic lens 100Aprovides panoramic capture/projection capability in a simple layout. Thetwo-surface design can be easily molded out of plastic for economicallarge-scale production, although any other optically transparentmaterial (e.g., glass) could be used. Furthermore, according to variousother embodiments of the invention, the panoramic lens can includeadditional surfaces/features.

For example, FIG. 1B shows a cross-section of a panoramic lens 100B inaccordance with another embodiment of the invention. Panoramic lens 100Bis symmetric about an axis of rotation 101B and includes a convexsurface 110B, a lower concave surface 120B, and an upper concave surface130B. Convex surface 110B is positioned between upper concave surface130B and lower concave surface 120B. Each of the surfaces follows itsown aspheric curve.

Convex surface 110B is transmissive (indicated by the thin line), upperconcave surface 130B is reflective (indicated by the dark line), andlower concave surface 120B includes an internally reflective portion120B(2) (indicated by the dark line) surrounding a transmissive portion120B(1) (indicated by the thin line). Just as with lens 100A shown inFIG. 1A, reflective upper concave surface 130B and internally reflectiveportion 120B(1) can be formed by applying a reflective coating to lens100B, while transmissive convex surface 110B and transmissive portion120B(2) can be left clear or can be coated with an anti-reflectivecoating to improve transmission characteristics.

In use, light from the surrounding scene (e.g., the light spanning anincluded angle A1B bounded by light rays R11B and R12B) enters lens 100Bthrough transparent convex surface 110B and is refracted towardsinternally reflective portion 120B(2) of lower concave surface 120B,which reflects the light towards upper concave surface 130B, whichreflects the light back towards lower concave surface 120B. The lightthen exits lens 100B from transmissive region 120B(1) of lower concavesurface 120B. In this manner, (monolithic) lens 100B captures (andsimilarly can project) a 360-degree surrounding panoramic scene into acolumn of light beams without requiring any additional optical elements.Note that the particular paths of light rays R11 and R12 shown in FIG.1A (and any subsequent figures) are for exemplary purposes only, as thespecific paths traced by individual lights rays will vary depending onthe specific shape of the lens.

FIG. 2 shows a cross-section of a panoramic lens 200 in accordance withanother embodiment of the invention. Panoramic lens 200 is symmetricabout an axis of rotation 201 and includes a convex surface 210 and aconcave surface 220. In exterior form and basic operation, panoramiclens 200 is substantially similar to panoramic lens 100A shown in FIG.1A. However, unlike lens 100A, only those portions of convex surface 210and concave surface 220 in the desired optical path are made reflectiveor transmissive. Other portions of convex surface 210 and concavesurface 220 are covered with an absorbing coating to minimize any strayreflected or refracted light that could degrade the imaging qualityprovided by lens 220.

For example, convex surface 210 includes a transmissive portion 210(1)(indicated by the thin line), an internally reflective portion 210(2)(indicated by the heavy line), and absorptive portions 210(3), 210(4),and 210(5) (indicated by the medium weight line). Thus, whiletransmissive portion 210(1) still surrounds internally reflectiveportion 210(2), the two portions are now separated by absorptive portion210(4). Similarly, concave surface 220 includes a transmissive portion220(1) (indicated by the thin line), an internally reflective portion220(2) (indicated by the heavy line), and an absorptive portion 220(3)(indicated by the medium-weight line). The specific dimensions of thevarious transmissive, reflective, and absorptive portions of convexsurface 210 and concave surface 220 can then be defined according to thedesired optical path within lens 200. Those dimensions then determinethe actual optical path followed by light in lens 200.

For example, if light rays R21 and R22 represent the boundaries of adesired included angle A2 for the 360-degree surrounding scene to becaptured by lens 200, those light rays define the desired optical pathwithin lens 200. Accordingly, transmissive portion 210(1) of convexsurface 210 is sized to capture (or project) included angle A2 (i.e.,sized just large enough to admit light within included angle A2 intolens 200). Thus, transmissive portion 210(1) is an annulus having anouter radius R4 and an inner radius R3, where radii R4 and R3 correspondto the points at which light rays R22 and R21, respectively, areincident on convex surface 210.

Internally reflective portion 220(2) of convex surface 220 then onlyneeds to be large enough to reflect the light transmitted bytransmissive portion 210(1). Internally reflective portion 220(2) is anannulus having an outer radius R7 and an inner radius R6, where radii R7and R6 coincide with the points at which light rays R22 and R21,respectively, are incident on concave surface 220. Therefore, internallyreflective portion 220(2) is sized to be equal to the area on convexsurface 220 exposed to the light transmitted by transmissive portion210(1) (i.e., the light from included angle A2).

In a similar manner, internally reflective portion 210(2) is an annulushaving an outer radius R2 and an inner radius R1, with radii R2 and R1bounding the portion of convex surface 210 on which the light reflectedby internally reflective portion 220(2) is incident. Finally,transmissive portion 220(1) is a curved disc having a radius R5, whereinradius R5 is just large enough to allow all the light reflected frominternally reflective portion 210(2) to pass through concave surface220.

Note that the specific dimensions of transmissive portions 210(1) and220(2) and internally reflective portions 210(2) and 220(2) depend onthe desired size and optical characteristics of panoramic lens 200. Forexample, according to an embodiment of the invention, for a desktopconferencing application, the dimensions listed in Table 2, below, couldbe specified for the lens defined in Table 1.

TABLE 2 SAMPLE LENS DIMENSIONS Radius Nominal Dimension R1 1.67 mm R26.91 mm R3 13.90 mm R4 20.86 mm R5 3.74 mm R6 same as R5 R7 15.72 mmAll portions of lens 200 not in the desired optical path (i.e.,absorptive portions 210(3), 210(4), 210(5), 220(3), and 220(4)) arecoated with an absorbing layer such as black paint to absorb any straylight.

Note that to capture the desired included angle A2 for the 360-degreesurrounding scene, transmissive region 210(1) extends almost but notquite to the actual intersection of convex surface 210 and concavesurface 220. Similarly, internally reflective portion 220(2) of concavesurface 220 does not extend all the way to the outer limits of concavesurface 220. Therefore, according to various embodiments of theinvention, the outer perimeter of lens 200 (i.e., the region in thevicinity of the intersection between convex surface 210 and concavesurface 220) can be modified or even removed so long as the modificationor removal does not interfere with the desired optical path of lightwithin lens 200.

FIG. 3 shows an imaging system 390 for capturing (or projecting) a360-degree surrounding scene, according to an embodiment of theinvention. Imaging system 390 includes a panoramic lens 200, a secondaryoptical system 340, and an imaging device 350. Imaging device 350 cancomprise any type of photosensing element, such as a photosensitive film(i.e., chemical based film) or a digital image sensor, and can becoupled to an optional image processor 351 (indicated by the dottedline) to provide additional digital image manipulation. Imaging device350 could alternatively comprise a source beam generator for emitting acolumn of light beams containing image data that is passed by secondaryoptical system 340 to lens 200, which then projects the image data as a360-degree panoramic scene.

Meanwhile, panoramic lens 200 in FIG. 3 is substantially similar topanoramic lens 200 described with respect to FIG. 2. The particularconfiguration (dimensions) of panoramic lens 200 will depend on therequirements of imaging system 390. For example, if imaging system 390is a video conferencing system, panoramic lens 200 could be optimized tomaximize the resolution of image data captured from an included angle(A2) substantially equal to 60-degrees—e.g., 45-degrees above thehorizon (angle A2(1)) through 15-degrees below the horizon (angleA2(2)).

Secondary optical system 340 can include any number and type of opticalelements. For exemplary purposes, secondary optical system 340 isdepicted as including a field flattening lens 341, a scaling lens 342, aset of color correcting lenses 343, 344, and 345, and an IR (infrared)filter 346. Therefore, light from a 360-degree panoramic scene enteringlens 200 via transparent region 210(1) and exiting from transparentregion 220(1) is corrected for image flatness, scale, and color accuracyby secondary optical system 340 before being detected or captured byimaging device 350.

As is well known in the art, various other arrangements and/orselections of optical elements can be included in secondary opticalsystem 340. Secondary optical system 340 simply provides an opticalpathway (that can provide various types of optical manipulations)between panoramic lens 200 and image processing system 360. For example,FIG. 4 shows a sample image 400 that could be captured from a 360-degreesurrounding scene by imaging device 350. Depending on the intended useof image 400, secondary optical system 340 could comprise anycombination of optical elements for manipulating the image (e.g.,focusing, astigmatism correcting, color correcting, image flattening,and/or diffracting lenses).

The various embodiments of the structures and methods of this inventionthat are described above are illustrative only of the principles of thisinvention and are not intended to limit the scope of the invention tothe particular embodiments described. Thus, the invention is limitedonly by the following claims and their equivalents.

1. A panoramic lens comprising a first aspheric surface about an axis ofrevolution and a second aspheric surface about the axis of revolution,wherein the first aspheric surface comprises a first transmissiveportion and a first internally reflective portion, the firsttransmissive portion and the first internally reflective portion havinga first continuous curvature, wherein the second aspheric surfacecomprises a second transmissive portion and a second internallyreflective portion, the second transmissive portion and the secondinternally reflective portion having a second continuous curvature, andwherein the first aspheric surface contacts the second aspheric surface.2. The panoramic lens of claim 1, wherein the first aspheric surface hasa convex curvature in a plane of the axis of revolution, wherein thefirst transmissive portion surrounds the first internally reflectiveportion, wherein the second aspheric surface has a concave curvature inthe plane of the axis of revolution, and wherein the second internallyreflective portion surrounds the second transmissive portion.
 3. Thepanoramic lens of claim 2, wherein the second internally reflectiveportion is adapted to reflect light between the first transmissiveportion and the first internally reflective portion, and wherein thefirst internally reflective portion is adapted to reflect light betweenthe second internally reflective portion and the second transmissiveportion.
 4. The panoramic lens of claim 3, wherein the firsttransmissive portion is sized to capture light from a first includedangle of a 360-degree surrounding image.
 5. The panoramic lens of claim4, wherein light transmitted by the first transmissive portion into thepanoramic lens is incident on a first region of the concave asphericsurface, and wherein the second internally reflective portion issubstantially the same as the first region of the concave asphericsurface.
 6. The panoramic lens of claim 5, wherein light reflected bythe second internally reflective portion onto the first aspheric surfaceis incident on a second region of the first aspheric surface, andwherein the first internally reflective portion is substantially thesame as the second region of the first aspheric surface.
 7. Thepanoramic lens of claim 6, wherein light reflected by the firstinternally reflective portion onto the concave aspheric surface isincident on a third region of the concave aspheric surface, and whereinthe second transmissive portion is substantially the same as the thirdregion of the concave aspheric surface.
 8. The panoramic lens of claim7, wherein the first included angle is at least 60-degrees.
 9. Thepanoramic lens of claim 2, wherein the first internally reflectiveportion and the second internally reflective portion are coated with areflective coating, and wherein portions of the panoramic lens notincluded in the first transmissive portion, the second transmissiveportion, the first internally reflective portion, or the secondinternally reflective portion are coated with an absorbing coating. 10.The panoramic lens of claim 9, wherein the first transmissive portionand the second transmissive portion are coated with an anti-reflectivecoating.
 11. An imaging system comprising: a panoramic lens; an imagingdevice; and a secondary set of optical elements providing an opticalpath between a photosensing element and the panoramic lens, wherein thepanoramic lens comprises: a convex aspheric surface about an axis ofrevolution, the convex aspheric surface comprising a first transmissiveportion surrounding a first internally reflective portion, wherein thefirst transmissive portion and the first internally reflective portionhave a first continuous curvature; and a concave aspheric surface aboutthe axis of revolution, the concave aspheric surface comprising a secondinternally reflective portion surrounding a second transmissive portion,wherein the second internally reflective portion and the secondtransmissive portion have a second continuous curvature, wherein theconvex aspheric surface is in contact with the concave aspheric surface.12. The imaging system of claim 11, wherein the second internallyreflective portion is adapted to reflect light between the firsttransmissive portion and the first internally reflective portion, andwherein the first internally reflective portion is adapted to reflectlight between the second internally reflective portion and the secondtransmissive portion.
 13. The imaging system of claim 11, wherein theimage processing system comprises a photosensing element for receivinglight from the second transmissive portion via the secondary set ofoptical elements.
 14. The imaging system of claim 13, wherein thesecondary set of optical elements comprises at least one of a imageflattening lens, a scaling lens, a color correcting lens set, anastigmatism correcting lens, a diffracting lens, and an infrared filter.15. The imaging system of claim 13, further comprising a digital imageprocessor coupled to the photosensing element for manipulating imagescaptured by the photosensing element.
 16. The imaging system of claim11, wherein the image processing system comprises a source beamgenerator for providing source beams to the second transmissive portionvia the secondary set of optical elements.
 17. A panoramic lenscomprising: a first aspheric surface about an axis of revolution, thefirst aspheric surface comprising a first transmissive portion and afirst internally reflective portion, wherein the first aspheric surfacehas a convex curvature in a plane of the axis of revolution, and whereinthe first transmissive portion surrounds the first internally reflectiveportion; and a concave aspheric surface about the axis of revolution,the concave aspheric surface comprising a second internally reflectiveportion surrounding a second transmissive portion, wherein the secondinternally reflective portion is adapted to reflect light between thefirst transmissive portion and the first internally reflective portion,wherein the first internally reflective portion is adapted to reflectlight between the second internally reflective portion and the secondtransmissive portion, wherein the first transmissive portion is sized tocapture light from a first included angle of a 360-degree surroundingimage, wherein light transmitted by the first transmissive portion intothe panoramic lens is incident on a first region of the concave asphericsurface, wherein the second internally reflective portion issubstantially the same as the first region of the concave asphericsurface, wherein light reflected by the second internally reflectiveportion onto the first aspheric surface is incident on a second regionof the first aspheric surface, wherein the first internally reflectiveportion is substantially the same as the second region of the firstaspheric surface, wherein light reflected by the first internallyreflective portion onto the concave aspheric surface is incident on athird region of the concave aspheric surface, wherein the secondtransmissive portion is substantially the same as the third region ofthe concave aspheric surface, and wherein the first included angle is60-degrees.
 18. An imaging system comprising: a panoramic lens; animaging device; and a secondary set of optical elements providing anoptical path between a photosensing element and the panoramic lens,wherein the panoramic lens comprises: a convex aspheric surface, theconvex aspheric surface comprising a first transmissive portionsurrounding a first internally reflective portion, wherein the firsttransmissive portion and the first internally reflective portion have afirst continuous curvature; and a concave aspheric surface, the concaveaspheric surface comprising a second internally reflective portionsurrounding a second transmissive portion, wherein the secondtransmissive portion and the second internally reflective portion have asecond continuous curvature, and wherein the convex aspheric surface isin contact with the concave aspheric surface.
 19. A panoramic lenscomprising: a first aspheric surface, the first aspheric surfacecomprising a first transmissive portion and a first internallyreflective portion, wherein the first aspheric surface has a convexcurvature, and wherein the first transmissive portion surrounds thefirst internally reflective portion; and a concave aspheric surface, theconcave aspheric surface comprising a second internally reflectiveportion surrounding a second transmissive portion, wherein the secondinternally reflective portion is adapted to reflect light between thefirst transmissive portion and the first internally reflective portion,wherein the first internally reflective portion is adapted to reflectlight between the second internally reflective portion and the secondtransmissive portion, wherein the first transmissive portion is sized tocapture light from a first included angle of a 360-degree surroundingimage, wherein light transmitted by the first transmissive portion intothe panoramic lens is incident on a first region of the concave asphericsurface, wherein the second internally reflective portion issubstantially the same as the first region of the concave asphericsurface, wherein light reflected by the second internally reflectiveportion onto the first aspheric surface is incident on a second regionof the first aspheric surface, wherein the first internally reflectiveportion is substantially the same as the second region of the firstaspheric surface, wherein light reflected by the first internallyreflective portion onto the concave aspheric surface is incident on athird region of the concave aspheric surface, wherein the secondtransmissive portion is substantially the same as the third region ofthe concave aspheric surface, and wherein the first included angle is60-degrees.
 20. A method of imaging comprising: passing light through atransmissive portion of a convex surface; refracting the light towardsan internally reflective portion of the convex surface; reflecting thelight towards an internally reflective portion of the convex surface;reflecting the light towards a transmissive portion of the concavesurface; and refracting the light with the transmissive portion of theconcave surface, wherein the transmissive portion and the internallyreflective portion of the concave surface have a first continuouscurvature, wherein the transmissive portion and the internallyreflective portion of the convex surface have a second continuouscurvature, and wherein the convex surface is in contact with the concavesurface.
 21. The method of claim 20, wherein the concave surfacecomprises a first aspheric surface about an axis of revolution, andwherein the convex surface comprises a second aspheric surface about theaxis of revolution.
 22. The method of claim 20, wherein the transmissiveportion of the convex surface is sized to capture light from a firstincluded angle of a 360-degree surrounding image.
 23. The method ofclaim 22, wherein the first included angle is at least 60-degrees. 24.The method of claim 20, further comprising imaging through use of apanoramic lens, wherein the internally reflective portion of the concavesurface and the internally reflective portion of the convex surface arecoated with a reflective coating, and wherein portions of the panoramiclens not included in the transmissive portion of the concave surface,the transmissive portion of the convex surface, the internallyreflective portion of the concave surface, or the internally reflectiveportion of the convex surface are coated with an absorbing coating. 25.The method of claim 24, wherein the transmissive portion of the concavesurface and the transmissive portion of the convex surface are coatedwith an anti-reflective coating.
 26. The method of claim 20, furthercomprising imaging through use of a panoramic lens, wherein lighttransmitted by the transmissive portion of the convex surface into thepanoramic lens is incident on a region of the concave surface, andwherein the internally reflective portion of the concave surface issubstantially the same as the region of the concave surface.
 27. Themethod of claim 20, wherein light reflected by the internally reflectiveportion of the convex surface onto the concave surface is incident on aregion of the concave surface, and wherein the transmissive portion ofthe concave surface is substantially the same as the region of theconcave surface.
 28. The method of claim 20, wherein light reflected bythe internally reflective portion of the concave surface onto the convexsurface is incident on a region of the convex surface, and wherein theinternally reflective portion of the convex surface is substantially thesame as the region of the convex surface.